Have ScriptPromiseResolver on the Oilpan heap always.

Source/core/streams/ReadableStreamImpl.h

Index: Source/core/streams/ReadableStreamImpl.h
diff --git a/Source/core/streams/ReadableStreamImpl.h b/Source/core/streams/ReadableStreamImpl.h
index 719fe8e040a940fe2c8cb9456434f1bfc9b3cee0..fc3d3f5e8d1ba69a473a1c9a330b22e1feec75ca 100644
--- a/Source/core/streams/ReadableStreamImpl.h
+++ b/Source/core/streams/ReadableStreamImpl.h
@@ -118,18 +118,12 @@ public:
     DEFINE_INLINE_VIRTUAL_TRACE()
     {
         visitor->trace(m_strategy);
-#if ENABLE(OILPAN)
         visitor->trace(m_pendingReads);
-#endif
         ReadableStream::trace(visitor);
     }
 
 private:
-#if ENABLE(OILPAN)
     using PendingReads = HeapDeque<Member<ScriptPromiseResolver>>;
-#else
-    using PendingReads = Deque<RefPtr<ScriptPromiseResolver>>;
-#endif
 
     // ReadableStream methods
     bool isQueueEmpty() const override { return m_queue.isEmpty(); }
@@ -180,7 +174,7 @@ bool ReadableStreamImpl<ChunkTypeTraits>::enqueue(typename ChunkTypeTraits::Pass
         return enqueuePostAction();
     }
 
-    RefPtrWillBeRawPtr<ScriptPromiseResolver> resolver = m_pendingReads.takeFirst();
+    ScriptPromiseResolver* resolver = m_pendingReads.takeFirst();
     ScriptState* scriptState = resolver->scriptState();
     ScriptState::Scope scope(scriptState);
     resolver->resolve(v8IteratorResult(scriptState, chunk));